[en] The Mo-W-N system has been investigated by nitriding Mo-W alloys of different compositions at 700⁰C with flowing ammonia. The nitrided samples were annealed at 1100⁰C under nitrogen at pressures of 30 and 300 bars, then analysed and investigated by x-rays. Up to 32% of molybdenum atoms could be replaced by tungsten atoms at a nitrogen pressure of 300 bars, while at 30 bars there was no appreciable solubility of tungsten in γ-M0₂N. (author)